The American Academy of Pediatrics recommended in August 2014 that middle and high schools should not commence before 8:30 a.m. According to the Brookings Institute, moving start time 1 hour later provides a 9 to 1 benefit to cost ratio and showed more improvement in grades than other efforts, like reducing classroom size.
The American Academy of Pediatrics also recommends that teens average 8 to 9 hours of sleep per night. Unlike adults, teens cannot fall asleep until around 11 p.m. That is because their bodies do not produce melatonin, the natural chemical that instructs the body to sleep, until around 11 p.m. Pre-8:00 a.m. start time does not allow for enough sleep.
When teens don’t get enough sleep, they risk serious health problems. Grades are also negatively affected. The negative effect of early start time on disadvantaged students is even greater. Schools seeking to bring up grades for disadvantaged students have an obvious solution: give kids more sleep.
Moving start time later has huge benefits. Students sleep more during the school week when classes start later. Students also get better grades. Attendance increases and tardiness decreases. Athletes have fewer sports-related injuries. Car accident rates drop.
Resource: the American Academy of Pediatrics policy statement.